The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Current video data compression technologies include H.261, H.263, MPEG-2, MPEG-4, and the like. In encoding images, the existing video compression technologies divide each image into fixedly sized macroblocks which are composed of rectangular 16×16 pixel areas of luma component and rectangular 8×8 pixel areas of chroma component. All of the luma and chroma components are spatially or temporally predicted, and the resultant predicted residuals undergo transform, quantization, and entropy coding before they are eventually compressed.
An encoding apparatus by the H.264/AVC compression standard subdivides each macroblock into blocks of smaller sizes 16×16, 8×8, and 4×4 to perform an intra prediction encoding wherein 16×16 pixel blocks are processed in one of four prediction modes and 8×8 pixel blocks and 4×4 pixel blocks in one of nine prediction modes. As for an inter prediction encoding, each macroblock may be first divided into blocks of pixel sizes 16×16, 16×8, 8×16, 8×8, 8×4, 4×8, and 4×4. Transform is carried out in units of 8×8 or 4×4 pixel blocks, and quantization of transform coefficients utilizes a scalar quantization. In this way, a video encoding apparatus in the process of intra prediction encoding or inter prediction encoding is supposed to encode not only the target images but also various pieces of information used for the intra prediction encoding and inter prediction encoding.
In addition, there is an outstanding necessity for compressing high-resolution videos such as 4K×2K videos, but no such technology has been developed that can effectively compress a large volume of high-resolution videos. Still, as the video size increases and units of division for encoding a large volume of videos increase, more information is necessary for the intra prediction encoding and inter prediction encoding, resulting in a reduction in the video compression efficiency. Therefore, there is a need for technological development that can improve the encoding efficiency and video compression efficiency.